海上油田Pickering响应型双相复合调驱体系研究与应用

Research and Application of Pickering Response Dual-phase Compound Profile Control and Flooding System in Oilfield

随着海上油田的注水开发,油藏经过长时间冲刷后产生了优势渗流区域,常规凝胶调驱体系在地下成胶效果不能满足该区域的封堵条件,影响调驱效果。为了提升优势渗流区域的调堵效果,室内筛选评价出初始黏度低、触变性弱的高线性聚合物,研发纳米交联剂与基于共价键响应的Pickering泡沫起泡剂,形成了Pickering泡沫-纳米凝胶双相复合调堵体系,并对复合体系的成胶性能、泡沫半衰期、体系形貌、提高采收率幅度等进行了室内评价。结果表明:凝胶成胶后的黏度大于8000 mPa·s;65℃条件下,泡沫半衰期为19 d,提高采收率幅度为36%,体系形貌具备完整桥连空间结构。双相凝胶复合调堵体系在渤海油田B平台进行应用,注入压力提升3 MPa,井组充满度提升23%,砂体日增油60 m^(3),有效期持续7个月,累计增油超过7000 m^(3),体系调堵效果显著,具备市场推广价值。

With the development of offshore oilfield by water injection, the reservoir has produced a dominant seepage area after long-term scouring, and the gel forming effect of conventional gel profile control and flooding system in the underground cannot meet the sealing conditions in this area, which affects the profile control and flooding effect. In order to improve the plugging control effect in the dominant seepage area, the high linear polymer with low initial viscosity and weak thixotropy was screened and evaluated in the laboratory, and the Pickering foam foaming agent based on covalent bond response was developed to form the Pickering foam-nano gel dual-phase composite plugging control system. In this paper, the gel-forming performance, foam half-life, system morphology and enhanced oil recovery range of the composite system were evaluated in laboratory. The evaluation results showed that the viscosity of the gel after gel-forming was greater than 8 000 mPa·s;At 65 ℃, the foam half-life was 19 days, and the enhanced oil recovery was 36%. The morphology of the system was a complete bridging spatial structure. Dual-phase gel composite plugging control system was applied in platform B of Bohai oilfield, the injection pressure was increased by 3 MPa, the well group fullness increased by 23%, the daily increased oil production of sand body reached 60 m^(3), the effective period lasted for 7 months, and the cumulative oil increase was more than 7 000 m^(3). The system has remarkable plugging control effect and market promotion value.